The Sim-Lab P1 is great. I can see the value that the X has for some people, but it also has no value to other people. I have lots mounted under my wheel deck and I have to be able to slide it forward and backwards easily. My rig sits on a very level concrete basement floor and doesn't need any leveling. So for me the upgrade would be a setback. Fortunately I have an original P1. I did add a piece of profile to each side under the pedal deck which is a very simple way to add height to it while keeping the ability to slide the deck forward and backwards easily. Win:Win In that video it was mentioned that they only sold the feet separately but not the new pedal deck. From my experience with Sim-Labs if you ask for something, typically they will sell you exactly what you want, but I never checked on this.
The pedal deck might work well on the outside of the frame like the original and thereby keep it's easy of adjustment. They would just need to include slightly longer profile.
I think it's likely that they moved the pedal mount inside the frame to easily accommodate SFX-100, PT-Actuator, D-Box systems. If I ever consider installing one of those, I may change my tune very suddenly.